Home > Tips & Tricks > Blue Green Chromis Care | Chromis viridis

Blue Green Chromis Care | Chromis viridis

Some fish just have it all. Colorful, easy to keep, reef safe, suitable for smaller tanks… can it get any more perfect? The blue green chromis is one of these species. If you’re a beginner looking for fish to stock your first marine aquarium with, this is an excellent choice.

Keep reading for everything you need to know about blue green chromis care!

Name (Common, Scientific)Blue green chromis, green chromis, Chromis viridis
Minimum tank size30 gallons
Minimum group size6
Temperature72-78 °F
Difficulty levelEasy

Blue green chromis (Chromis viridis) description

The blue green chromis is a small species of damselfish. They lend their name from their shimmery, almost iridescent coloration that is indeed somewhere between blue and green depending on the light.

This is a small species: they grow to a maximum length of around 4”, although most don’t make it past 3”.

Did you know? The blue green chromis is not always blue and green. Males, during the mating season, completely change color! They turn more of a yellow green with some black coloration. If you see your males turning this color in the aquarium, that’s a good indication your group of chromis are getting frisky.

Blue green chromis fish | Chromis viridis

Blue green chromis (Chromis viridis) aquarium

The blue green chromis is naturally found in shallow coral reefs in various areas in the Indo-Pacific. In the aquarium they prefer a similar environment with plenty of corals and rock formations to dart around.

Although they’re mainly considered inhabitants of the middle water layer, you’ll find your blue green chromis actively exploring all corners of the aquarium. Quite mesmerizing to watch!

Did you know? The blue green chromis is known for being a very hardy species that’s forgiving to the occasional beginner mistake. Still, keep water quality high, make sure your tank is fully cycled before introducing any fish and make sure to do regular water changes and maintenance.

Blue green chromis (Chromis viridis) compatibility

Damselfish are generally not exactly known for their ability to play nice with their neighbors, with most species being rather territorial. The blue green chromis is a nice exception to this! They’re peaceful and not known to bother their tankmates, meaning you can combine them with a host of other calm reef species.

In the wild, the blue green chromis is not a schooling fish but it does move in large, loosely congregated shoals. Although some sources mention that you can keep a single chromis in a nano aquarium, we prefer going for at least a 30 gallon to allow us to keep a group of around 6 specimens. Keeping such a social fish on its own just doesn’t seem ideal!

This reef dweller is not known for bothering corals or invertebrates. The only species you should actively avoid are larger or very aggressive ones, to prevent your chromis from being bullied or attacked.

Blue green chromis fish | Chromis viridis

Blue green chromis (Chromis viridis) diet

In the wild, the blue green chromis is an omnivore that mostly feeds on small critters like plankton, copepods and amphipods, although it also consumes algae.

In the aquarium this is not a difficult feeder at all. It should accept pretty much anything you offer it, including commercial flake and pellet foods for marine fish. You can also opt to include (thawed) frozen foods like artemia, krill and mysis as well as algae tabs or blanched veggies.

Tip: Don’t over-clean your aquarium. Your blue green chromis will appreciate it if you leave a patch of algae for them to graze on.


A bustling reef tank with a group of shimmering blue green chromis really is quite a sight to see. This truly is one of our favorite easy fish species for both beginners and experienced aquarists.

Are you dreaming of an aquarium in your home and office? FantaSEA can help. Contact us here with your ideas and let’s make it happen!

Photo of author

Marijke Puts

Hey! I'm Marijke, FantaSEA's resident blog writer. I'm a full-time pop science author, part-time PADI diver and snorkeler, and have been keeping fish since I was a kid. When I'm not writing fish care guides, you can usually find me underwater or trying to figure out how to fit more tanks into my house.

You may also like

Sorry, no posts were found.

Leave a Comment